A side skirt system for reducing drag on a trailer includes a side skirt wall configured to be coupled to one side of the trailer to extend below a side wall of the trailer along a length of the trailer. A mounting bracket assembly of the system is coupled to the side skirt wall and is configured to be coupled to a floor assembly of the trailer. The mounting bracket assembly is configured to tilt laterally outwardly and laterally inwardly with respect to a generally vertical axis parallel to the side wall of the trailer.